This invention relates to a reaction product of a grafted dextranomer and a phthalocyanine dye. The invention also relates to the use of this reaction product for selectively adsorbing mutagenic heterocyclic amines.
For some time, the mutagenic substances present in our environment and in certain of our foods have become a major subject of concern on account of their effect on the health of human beings as potential carcinogenic agents. Accordingly, there is a considerable need for techniques enabling such substances to be analyzed and eliminated.
It is known that compounds of the phthalocyanine type have the property of forming stable complexes with polycyclic mutagenic substances. This property has been utilized for preparing products for the selective adsorption of polycyclic mutagenic substances present in essentially aqueous media by reaction of phthalocyanines containing a reactive group with organic or inorganic solid materials. For example, European Patent 90 610 describes a method for adsorbing polycyclic mutagenic substances using an adsorption product prepared from cellulose and a phthalocyanine dye containing a reactive group. According to U.S. Pat. No. 4,490,525, products for the adsorption of polycyclic mutagenic substances are prepared from polysaccharides of the agarose or dextrin type chemically activated beforehand, onto which reactive phthalocyanines are grafted. According to European Patent 157 549, phthalocyanines containing a reactive group are chemically fixed to silica gel onto which aminopropyl residues are grafted. However, with all these adsorbents for the polycyclic mutagenic substances mentioned by way of example, affinity for those mutagenic substances is conferred almost entirely by the phthalocyanine residue and does not utilize any intrinsic properties of affinity for the mutagenic substances mentioned which the solid starting material used for the production of the adsorbent product might have. In addition, these materials not only have affinity for the polycyclic mutagenic substances mentioned, but also for a certain number of other substances which might also be present in the media containing the mutagenic substances mentioned, so that the selectivity of these adsorbent materials with respect to the mutagenic substances mentioned is often mediocre. On the other hand, the adsorbent materials mentioned by way of example only work when the mutagenic substances are present in essentially aqueous media. Accordingly, they cannot be used in every case where contact with the mutagenic substances would have to take place in an organic solvent.
It is known from the literature that other adsorbent materials than those containing phthalocyanine residues have a certain affinity for polycyclic mutagenic substances. For example, in Carcinogenesis 1989, 10(7), 1175-1182, G. A. Gross et al. showed that a material produced from dextranomer, which is a polymer of the dextran type crosslinked by 2-hydroxy-1,3-propylene bridges and onto which hydroxypropyl groups are grafted (hereinafter referred to as grafted dextranomer), shows a higher adsorption selectivity with respect to polycyclic mutagenic substances than the majority of other known adsorbents which do not contain phthalocyanine residues
For example, the utilization of this grafted dextranomer for analytical purposes enables the precision of methods for detecting polycyclic mutagenic substances in food products to be simplified and increased. However, in some cases, for example when these mutagenic substances are present in media of high chemical complexity or when their concentration in these media is particularly low, the selectivity of this grafted dextranomer with respect to the mutagenic substances mentioned may no longer be sufficient to enable the substances in question to be detected by analytical methods.